The Prime Minister said the country could be hit with further sanctions over its role in the alleged incident.
He told MPs on Monday: “I can confirm our assessment that it is highly likely to have been coordinated in Iran, almost certainly directed by Iran’s Islamic Revolutionary Guard (IRGC).
“We will not tolerate these threats on our soil.
“We will crack down on Iran’s use of criminal networks, using our full range of powers to target them and their funding streams, and we will bring further sanctions to restrict the capacity of Iran and the IRGC to do us harm.”
The Iranian ambassador to the UK has been summoned to make clear that “Britain will not tolerate threats on our soil”, Foreign Secretary Ed Miliband said.
Two Iranian men were sanctioned by the UK Government on Monday.
Prime Minister Andy Burnham making a statement in the House of Commons
PA
The sanctions for Ruhollah Bazghandi, the Head of Counterespionage Operations within the IRGC, and Shahram Ali Reza Tamarzadeh Jakki, the facilitator of the Zindashti criminal network, include asset freezing, a ban on them entering Britain and both men being disqualified from managing any business in the UK.
Mr Burnham added that he has discussed the escalating situation between Saudi Arabia and the Yemeni Houthis with Donald Trump.
“I confirmed Britain's decision to send air defence and a Voyager aircraft to Saudi Arabia to provide air-to-air refuelling support," the Prime Minister told MPs.
"I can confirm today that it has already completed 14 operational missions."
Seven men, all in their 20s and from London, have been arrested on suspicion of preparation of terrorist acts by officers investigating the suspected terror plot at RAF Fairford.
Five were arrested on Sunday, September 27, one on Thursday, October 1 and another on Tuesday, October 6.
They have all been released on police bail.
Three suspicious vans were stopped near the airbase in Gloucestershire on Sunday, September 27.
Announcing the latest arrest last week, Senior National Coordinator for Counter Terrorism Policing, Vicki Evans, said: “This remains a live investigation and our specialist teams continue to pursue multiple lines of inquiry into the circumstances surrounding events near RAF Fairford.
“Once again, I’d like to thank the public for their continued support and patience whilst we work through this highly complex investigation.”
She added: “We’re acutely aware of the public interest in this investigation, and we are working around the clock, and at pace, to identify the motivation behind events in Gloucestershire.
“We remain committed to investigating all possible angles.”